Door-spring



UNITED STATES PATENT EEICE.

DAVID G. SMITH, OF GARBONDALE, PENNSYLVANIA.

DOOR-SPRING.

SPECIFICATION forming part of Letters Patent No. 247,123, dated September 13, 1881.

Application lcd June 15, 1881.

To all whom it may concern:

Be it known that I, DAVID G. SMITH, a citizen of the United States of America, residing at Carbondale, in the county of Lackawanna and State of Pennsylvania, haveinvented certain new and useful Improvements in Door- Springs; and Ido hereby declare the following to be a full, clear, and exact description ofthe invention, such as willenable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or tigures ot' reference marked thereon, which form a part of this specification.

My invention relates to an improvement in springs for doors; and it consists in attaching a steel rod or other suitable spring to a door and connecting it to an arm or casting on the door-jamb in such a manner as to cause the torsion ofthe spring caused by twisting it to keep the door either open or shut after having passed a certain point, as will be more fully described hereinafter.

The accompanying drawings illustrate my invention.

Figure 1 is a front elevation ot' a portion of a door with my improvement attached. Fig. 2 is a top-plan view, showing the door in section and open in dotted lines. Fig.3 is an end view, lookingiu the direction indicated by the arrow in Fig. 1.

Like letters ot' reference indicate like parts in all the figures.

A represents the door, of which B is the jainb, the door being hinged at C. To any ner end of the rod a is rigidly secured a disk, e, having lugs f upon opposite sides, to which the forked end g of the connecting-rod h is Through the lower end, i,

hinged, as shown.

(Model.)

of the rod h is passed a link, 7c, which connects the connecting-rod h to the bracket Z, secured to the door-jamb, the opposite end of the link to that which is connected to the arm h being passed through an elongated hole or slot, m, made in the end of the bracket-arm Z.

In the operation ot' my device, as the door is opened and the spring a twisted, the lower end ofthe rod h, attached to thelink k, will loc carried downward, describing the arc ot' a circle, as shown by dotted lines in the drawings. When the door passes the pointatright angles with the door-frame, the link k allowing the rod It to approach the door, the spring a will untwist, and in so doing will force the door wide open, holding it in that position; There will then be no tension upon the spring. As the door recedes from the lower end ot' the rod h, attached to the link 7c, in the act ot' closing, the tension upon the spring will be renewed and increased until the door passes the rightangle line. By the action of the door, in carrying the rod h back to its normal position, (in which it is aided and guided by the link In) the spring untwists with more force than it' the end of the rod h were stationary and no link used.

I am aware ot' Patent No. 179,824, July '11, 1S76,issued to J. B. Starkweather, t'or improvement in door-springs, and I do not claim any-- thing iu said patent. l

Having thus described my invention, I claim- In a door-spring, the link 7c, pivoted in the slot m ot' the bracket-arm I, and to the connecting-rod h, through the hole t', operating to relieve the tension upon the spring a when the door is open, and giving greater power to the spring when the door is closing, substantially as set forth.

In testimony whereof I have affixed my signature in presence ot' two witnesses.

` DAVID G. SMITH. Witnesses: i

HENRY J. BAER, JAMES R. BURNETT. 

